I have SL280, not modified in any way, which when first started has full use of heater etc. BUT after 15 or 20 miles the heater functions stop altogether. Stangely the fan still operates but it seems that the direction of the air is blocked!!!! No heat, no circulation cant quite understand it. The next day start the car and climate controls functions as usual!!!!!!!!!!!
The climate control has a diagnosis feature you can use and from memory it will probably point to being the evaporator temperature sensor based on your symptoms (though there are other possibilities).
In the morning when the car is cold do the following:
Turn the ignition to position 2.
Set the temp to 22 degrees (press both temperature buttons to do this automatically)
Hold the REST button for more than 6s.
The climate control will enter it's diagnostic feature and the left side of the display will alternately display the test number i.e '01' and then the parameter value.
Use the blower speed button to scroll through the parameter list - the evaporator temperature sensor is test 5 and it should return a sensible value (working temp is between 2 and 12 degrees C but if it has sat there then it will be an ambient reading).
Parameters
01: Cabin temp sensor
02: Outside temp sensor
03: Heater core temp sensor
05: Evaporator temp sensor
06: ECT temp sensor
07: Refrigerant pressure meassured in BAR
08: Refrigerant temp sensor
etc etc
..
.
You can repeat the above after running the car and aircon for a few minutes to compare values - again it should display a logical value.
An MBOC member brought this to my attention and it's quite handy!
In the morning when the car is cold do the following:
Turn the ignition to position 2.
Set the temp to 22 degrees (press both temperature buttons to do this automatically)
Hold the REST button for more than 6s.
The climate control will enter it's diagnostic feature and the left side of the display will alternately display the test number i.e '01' and then the parameter value.
Use the blower speed button to scroll through the parameter list - the evaporator temperature sensor is test 5 and it should return a sensible value (working temp is between 2 and 12 degrees C but if it has sat there then it will be an ambient reading).
Parameters
01: Cabin temp sensor
02: Outside temp sensor
03: Heater core temp sensor
05: Evaporator temp sensor
06: ECT temp sensor
07: Refrigerant pressure meassured in BAR
08: Refrigerant temp sensor
etc etc
..
.
You can repeat the above after running the car and aircon for a few minutes to compare values - again it should display a logical value.
An MBOC member brought this to my attention and it's quite handy!
A silly value would be something like 40 or 50 degrees.
Sorry I was in a rush earlier as I had to go out and posted the wrong diagram so deleted it in-case you got confused.
The original part number was A1298300072 - it has been superceeded by A2108300572 which is £28. It is located under the dash on the drivers side by the centre console housing - you just need to drop the trim panel for access.
Part is 250 on this diagram:
Sorry I was in a rush earlier as I had to go out and posted the wrong diagram so deleted it in-case you got confused.
The original part number was A1298300072 - it has been superceeded by A2108300572 which is £28. It is located under the dash on the drivers side by the centre console housing - you just need to drop the trim panel for access.
Part is 250 on this diagram:
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I tested those reading this morning 05 Evaporator sensor reads 21 degrees I will wait till my wife gets to work and ask her to test again.
1st test
01 read 11deg, 02 11deg, 03 11deg, 05 21deg, 06 11deg, 07 read 03.5, and 08 read 09deg.
She then drove to work 6 miles (approx)
Now the readings are 01-19deg, 02 11deg, 03 56deg, 05 23deg 06 88deg, 07 reads 05.6 and 08 reads 19 degrees. do they mean anything to you!?
1st test
01 read 11deg, 02 11deg, 03 11deg, 05 21deg, 06 11deg, 07 read 03.5, and 08 read 09deg.
She then drove to work 6 miles (approx)
Now the readings are 01-19deg, 02 11deg, 03 56deg, 05 23deg 06 88deg, 07 reads 05.6 and 08 reads 19 degrees. do they mean anything to you!?
It looks like you need a new ETS. If the cabin temp was 11 degrees then the ambient temperature of the ETS should have been around this value and then between 2 and 12 when the aircon had been running. Probably the cheapest fix there is for the climate control!
GrahamC230K
MB Enthusiast
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- 9,755
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Threads like these deserve to be rated. It's got 5 stars from me.
As Graham says this is amazing help you give, and I will somehow repay the kindness. I do have someone who queries this solution and questions whether it could be the vacuum unit that is shutting down and that may be the fault too!! This does not however undermine the suggestion you say. I just wonder what you feel, as you seem to have done a spock mind melt with Mercedes!!! Would the ets unit shut down the vacuum seals?
Last edited:
- Joined
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- 20,604
- Location
- Portsmouth, Hampshire.
- Car
- E55K SL500 E250X2 Smart44 Brabus Track car E450Cabriolet X350 Pick up
After looking at the ETS number(s) stats007 is spot bolloc on!!!
Def an ETS fault. When they go wrong they make the a/c do the strangest things.
Def an ETS fault. When they go wrong they make the a/c do the strangest things.
Vacuum faults are usually consistent in their behaviour and not temperature related across the whole vent system. The complete shutdown of airflow at running temperature can really only be one of two things - the ETS or the emissions control. The ETS was subject to a recall and hence the part number superceeded.
Whilst I can't guarantee this is the fault it's certainly the first thing I would replace given the circumstances.
Whilst I can't guarantee this is the fault it's certainly the first thing I would replace given the circumstances.
- Joined
- Feb 8, 2007
- Messages
- 20,604
- Location
- Portsmouth, Hampshire.
- Car
- E55K SL500 E250X2 Smart44 Brabus Track car E450Cabriolet X350 Pick up
Bet ya polishing ya halo......
If the problem gets fixed I'll be happy!
If the problem gets fixed for £38 quid ish I'll be ecstatic. I will of course send something to you, for all your time. I am so grateful for your help, fix or not its so nice to find there are still so many good people in this shi##y world (sorry to get so emotional)
